I am very interested in building an extruder type 3D printer using my existing CNC mill. There are basically only two items missing:
1: A heater with temperature control. The heater is typically controlled to hold the temperature around 240C. Either one of the available extruder head controller boards can be used or an off the shelf PID heater controller (about $30 on eBay). It might also be directly controlled by the pulse width function similarly to how laser cutters are controlled. It would be very simple to have a temperature feedback using a voltage to frequency converter that produces “index” pulses to show temperature: 240RPM= 240C temperature.
2: A motor to feed the filament into the heater. I think the head can be greatly simplified by using a simple machined bracket and a very small stepper motor. In our case the stepper could be directly driven by existing electronics and the A axis function in Mach3.
Here are examples of the extruder heads. They are all open source with full documentation. Typically the mechanics are unnecessarily big or too many pieces since they are usually designed to be easily duplicated by hobbyists with limited tooling.
http://objects.reprap.org/wiki/Mendel_extruderhttp://store.makerbot.com/toolheads/plastruder-kit-mk3.htmlhttp://www.thingiverse.com/thing:1332http://www.bitsfrombytes.com/index.php?option=com_content&view=article&id=70:v3-extruder-info&catid=22:version-3-rapman-build-infoIt is a big PDF file.
It should be very easy for us in this group to do it. Typically we have the CNC experience and we have good equipment to make any custom required parts.
The typical 3D printer hobbyist does not have the mechanical equipment or CNC experience. Most of them are starting from scratch.
Here is some info on conversions done with EMC instead of Mach3:
http://objects.reprap.org/wiki/EMCRepStrapIs there any information on a conversion like that using Mach3? I do not want to start from scratch if not needed.
Bertho